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450 lines
11 KiB
450 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/***************************************************************************** |
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* USBLCD Kernel Driver * |
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* Version 1.05 * |
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* (C) 2005 Georges Toth <[email protected]> * |
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* * |
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* This file is licensed under the GPL. See COPYING in the package. * |
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* Based on usb-skeleton.c 2.0 by Greg Kroah-Hartman ([email protected]) * |
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* * |
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* * |
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* 28.02.05 Complete rewrite of the original usblcd.c driver, * |
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* based on usb_skeleton.c. * |
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* This new driver allows more than one USB-LCD to be connected * |
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* and controlled, at once * |
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*****************************************************************************/ |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/slab.h> |
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#include <linux/errno.h> |
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#include <linux/mutex.h> |
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#include <linux/rwsem.h> |
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#include <linux/uaccess.h> |
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#include <linux/usb.h> |
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#define DRIVER_VERSION "USBLCD Driver Version 1.05" |
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#define USBLCD_MINOR 144 |
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#define IOCTL_GET_HARD_VERSION 1 |
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#define IOCTL_GET_DRV_VERSION 2 |
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static const struct usb_device_id id_table[] = { |
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{ .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(usb, id_table); |
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struct usb_lcd { |
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struct usb_device *udev; /* init: probe_lcd */ |
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struct usb_interface *interface; /* the interface for |
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this device */ |
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unsigned char *bulk_in_buffer; /* the buffer to receive |
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data */ |
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size_t bulk_in_size; /* the size of the |
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receive buffer */ |
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__u8 bulk_in_endpointAddr; /* the address of the |
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bulk in endpoint */ |
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__u8 bulk_out_endpointAddr; /* the address of the |
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bulk out endpoint */ |
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struct kref kref; |
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struct semaphore limit_sem; /* to stop writes at |
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full throttle from |
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using up all RAM */ |
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struct usb_anchor submitted; /* URBs to wait for |
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before suspend */ |
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struct rw_semaphore io_rwsem; |
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unsigned long disconnected:1; |
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}; |
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#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref) |
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#define USB_LCD_CONCURRENT_WRITES 5 |
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static struct usb_driver lcd_driver; |
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static void lcd_delete(struct kref *kref) |
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{ |
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struct usb_lcd *dev = to_lcd_dev(kref); |
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usb_put_dev(dev->udev); |
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kfree(dev->bulk_in_buffer); |
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kfree(dev); |
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} |
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static int lcd_open(struct inode *inode, struct file *file) |
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{ |
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struct usb_lcd *dev; |
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struct usb_interface *interface; |
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int subminor, r; |
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subminor = iminor(inode); |
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interface = usb_find_interface(&lcd_driver, subminor); |
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if (!interface) { |
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pr_err("USBLCD: %s - error, can't find device for minor %d\n", |
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__func__, subminor); |
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return -ENODEV; |
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} |
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dev = usb_get_intfdata(interface); |
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/* increment our usage count for the device */ |
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kref_get(&dev->kref); |
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/* grab a power reference */ |
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r = usb_autopm_get_interface(interface); |
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if (r < 0) { |
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kref_put(&dev->kref, lcd_delete); |
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return r; |
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} |
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/* save our object in the file's private structure */ |
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file->private_data = dev; |
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return 0; |
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} |
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static int lcd_release(struct inode *inode, struct file *file) |
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{ |
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struct usb_lcd *dev; |
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dev = file->private_data; |
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if (dev == NULL) |
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return -ENODEV; |
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/* decrement the count on our device */ |
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usb_autopm_put_interface(dev->interface); |
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kref_put(&dev->kref, lcd_delete); |
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return 0; |
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} |
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static ssize_t lcd_read(struct file *file, char __user * buffer, |
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size_t count, loff_t *ppos) |
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{ |
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struct usb_lcd *dev; |
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int retval = 0; |
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int bytes_read; |
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dev = file->private_data; |
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down_read(&dev->io_rwsem); |
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if (dev->disconnected) { |
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retval = -ENODEV; |
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goto out_up_io; |
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} |
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/* do a blocking bulk read to get data from the device */ |
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retval = usb_bulk_msg(dev->udev, |
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usb_rcvbulkpipe(dev->udev, |
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dev->bulk_in_endpointAddr), |
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dev->bulk_in_buffer, |
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min(dev->bulk_in_size, count), |
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&bytes_read, 10000); |
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/* if the read was successful, copy the data to userspace */ |
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if (!retval) { |
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if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) |
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retval = -EFAULT; |
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else |
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retval = bytes_read; |
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} |
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out_up_io: |
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up_read(&dev->io_rwsem); |
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return retval; |
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} |
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static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
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{ |
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struct usb_lcd *dev; |
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u16 bcdDevice; |
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char buf[30]; |
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dev = file->private_data; |
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if (dev == NULL) |
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return -ENODEV; |
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switch (cmd) { |
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case IOCTL_GET_HARD_VERSION: |
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bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice); |
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sprintf(buf, "%1d%1d.%1d%1d", |
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(bcdDevice & 0xF000)>>12, |
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(bcdDevice & 0xF00)>>8, |
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(bcdDevice & 0xF0)>>4, |
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(bcdDevice & 0xF)); |
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if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0) |
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return -EFAULT; |
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break; |
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case IOCTL_GET_DRV_VERSION: |
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sprintf(buf, DRIVER_VERSION); |
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if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0) |
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return -EFAULT; |
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break; |
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default: |
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return -ENOTTY; |
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} |
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return 0; |
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} |
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static void lcd_write_bulk_callback(struct urb *urb) |
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{ |
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struct usb_lcd *dev; |
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int status = urb->status; |
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dev = urb->context; |
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/* sync/async unlink faults aren't errors */ |
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if (status && |
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!(status == -ENOENT || |
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status == -ECONNRESET || |
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status == -ESHUTDOWN)) { |
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dev_dbg(&dev->interface->dev, |
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"nonzero write bulk status received: %d\n", status); |
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} |
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/* free up our allocated buffer */ |
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usb_free_coherent(urb->dev, urb->transfer_buffer_length, |
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urb->transfer_buffer, urb->transfer_dma); |
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up(&dev->limit_sem); |
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} |
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static ssize_t lcd_write(struct file *file, const char __user * user_buffer, |
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size_t count, loff_t *ppos) |
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{ |
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struct usb_lcd *dev; |
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int retval = 0, r; |
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struct urb *urb = NULL; |
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char *buf = NULL; |
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dev = file->private_data; |
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/* verify that we actually have some data to write */ |
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if (count == 0) |
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goto exit; |
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r = down_interruptible(&dev->limit_sem); |
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if (r < 0) |
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return -EINTR; |
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down_read(&dev->io_rwsem); |
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if (dev->disconnected) { |
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retval = -ENODEV; |
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goto err_up_io; |
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} |
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/* create a urb, and a buffer for it, and copy the data to the urb */ |
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urb = usb_alloc_urb(0, GFP_KERNEL); |
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if (!urb) { |
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retval = -ENOMEM; |
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goto err_up_io; |
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} |
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buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL, |
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&urb->transfer_dma); |
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if (!buf) { |
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retval = -ENOMEM; |
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goto error; |
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} |
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if (copy_from_user(buf, user_buffer, count)) { |
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retval = -EFAULT; |
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goto error; |
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} |
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/* initialize the urb properly */ |
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usb_fill_bulk_urb(urb, dev->udev, |
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usb_sndbulkpipe(dev->udev, |
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dev->bulk_out_endpointAddr), |
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buf, count, lcd_write_bulk_callback, dev); |
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urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; |
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usb_anchor_urb(urb, &dev->submitted); |
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/* send the data out the bulk port */ |
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retval = usb_submit_urb(urb, GFP_KERNEL); |
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if (retval) { |
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dev_err(&dev->udev->dev, |
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"%s - failed submitting write urb, error %d\n", |
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__func__, retval); |
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goto error_unanchor; |
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} |
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/* release our reference to this urb, |
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the USB core will eventually free it entirely */ |
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usb_free_urb(urb); |
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up_read(&dev->io_rwsem); |
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exit: |
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return count; |
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error_unanchor: |
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usb_unanchor_urb(urb); |
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error: |
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usb_free_coherent(dev->udev, count, buf, urb->transfer_dma); |
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usb_free_urb(urb); |
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err_up_io: |
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up_read(&dev->io_rwsem); |
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up(&dev->limit_sem); |
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return retval; |
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} |
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static const struct file_operations lcd_fops = { |
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.owner = THIS_MODULE, |
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.read = lcd_read, |
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.write = lcd_write, |
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.open = lcd_open, |
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.unlocked_ioctl = lcd_ioctl, |
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.release = lcd_release, |
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.llseek = noop_llseek, |
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}; |
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/* |
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* usb class driver info in order to get a minor number from the usb core, |
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* and to have the device registered with the driver core |
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*/ |
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static struct usb_class_driver lcd_class = { |
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.name = "lcd%d", |
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.fops = &lcd_fops, |
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.minor_base = USBLCD_MINOR, |
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}; |
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static int lcd_probe(struct usb_interface *interface, |
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const struct usb_device_id *id) |
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{ |
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struct usb_lcd *dev = NULL; |
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struct usb_endpoint_descriptor *bulk_in, *bulk_out; |
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int i; |
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int retval; |
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/* allocate memory for our device state and initialize it */ |
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dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
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if (!dev) |
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return -ENOMEM; |
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kref_init(&dev->kref); |
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sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES); |
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init_rwsem(&dev->io_rwsem); |
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init_usb_anchor(&dev->submitted); |
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dev->udev = usb_get_dev(interface_to_usbdev(interface)); |
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dev->interface = interface; |
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if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) { |
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dev_warn(&interface->dev, "USBLCD model not supported.\n"); |
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retval = -ENODEV; |
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goto error; |
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} |
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/* set up the endpoint information */ |
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/* use only the first bulk-in and bulk-out endpoints */ |
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retval = usb_find_common_endpoints(interface->cur_altsetting, |
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&bulk_in, &bulk_out, NULL, NULL); |
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if (retval) { |
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dev_err(&interface->dev, |
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"Could not find both bulk-in and bulk-out endpoints\n"); |
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goto error; |
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} |
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dev->bulk_in_size = usb_endpoint_maxp(bulk_in); |
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dev->bulk_in_endpointAddr = bulk_in->bEndpointAddress; |
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dev->bulk_in_buffer = kmalloc(dev->bulk_in_size, GFP_KERNEL); |
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if (!dev->bulk_in_buffer) { |
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retval = -ENOMEM; |
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goto error; |
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} |
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dev->bulk_out_endpointAddr = bulk_out->bEndpointAddress; |
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/* save our data pointer in this interface device */ |
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usb_set_intfdata(interface, dev); |
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/* we can register the device now, as it is ready */ |
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retval = usb_register_dev(interface, &lcd_class); |
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if (retval) { |
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/* something prevented us from registering this driver */ |
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dev_err(&interface->dev, |
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"Not able to get a minor for this device.\n"); |
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goto error; |
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} |
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i = le16_to_cpu(dev->udev->descriptor.bcdDevice); |
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dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found " |
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"at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8, |
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(i & 0xF0)>>4, (i & 0xF), dev->udev->devnum); |
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/* let the user know what node this device is now attached to */ |
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dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n", |
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interface->minor); |
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return 0; |
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error: |
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kref_put(&dev->kref, lcd_delete); |
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return retval; |
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} |
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static void lcd_draw_down(struct usb_lcd *dev) |
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{ |
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int time; |
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time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000); |
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if (!time) |
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usb_kill_anchored_urbs(&dev->submitted); |
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} |
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static int lcd_suspend(struct usb_interface *intf, pm_message_t message) |
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{ |
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struct usb_lcd *dev = usb_get_intfdata(intf); |
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if (!dev) |
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return 0; |
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lcd_draw_down(dev); |
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return 0; |
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} |
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static int lcd_resume(struct usb_interface *intf) |
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{ |
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return 0; |
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} |
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static void lcd_disconnect(struct usb_interface *interface) |
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{ |
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struct usb_lcd *dev = usb_get_intfdata(interface); |
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int minor = interface->minor; |
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/* give back our minor */ |
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usb_deregister_dev(interface, &lcd_class); |
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down_write(&dev->io_rwsem); |
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dev->disconnected = 1; |
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up_write(&dev->io_rwsem); |
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usb_kill_anchored_urbs(&dev->submitted); |
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/* decrement our usage count */ |
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kref_put(&dev->kref, lcd_delete); |
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dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor); |
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} |
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static struct usb_driver lcd_driver = { |
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.name = "usblcd", |
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.probe = lcd_probe, |
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.disconnect = lcd_disconnect, |
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.suspend = lcd_suspend, |
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.resume = lcd_resume, |
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.id_table = id_table, |
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.supports_autosuspend = 1, |
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}; |
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module_usb_driver(lcd_driver); |
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MODULE_AUTHOR("Georges Toth <[email protected]>"); |
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MODULE_DESCRIPTION(DRIVER_VERSION); |
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MODULE_LICENSE("GPL");
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